Improvement in saw-mill dogs



11. SNYDER. SAW-MILL DOGS.

Patmea July 3,1a71.

No. 192,795.V

' .UNITED ,.SrrATEs" PATENT HENRY SNYDER, OF FOlVLERSVILLE, lMICEIIGAN.

'j YIMPRo-VEMENT 15N sAw-mluunoes.

' ,-Specicationforming'part `of Letters Patent No 21923795, `dated July3, 1.877 application filed J j May 8,1877.

To all whom 'it'maj/ `concern Be it known that 1, `HENRY "SNYDER, of

' Fowlersville, `in "the county 'of Livingston and being in positions tosecure the log firmly to the head-block;l Fig. 3,a horizontal sectiontaken at the line a: w of Fig. l; and Fig. 4, a

similar section taken at the line y y of Fig. 2.

The device has two dogs adapted to hold the upper and the lower part ofthe log upon the head-block, the object being to Vhold the lower portionof the log from slipping away from the head-block, which is f'ound.to bea great difficulty in saw-mills, especially in saw- Y ing crooked logsthe bottom is liable to slip,

and to bind and injure or break the saw, causing delay, and requiringthe log to be readj usted and secured.

ln my improved construction the lower dog is made adjustable, to suitdiii'erent size logs, and to adapt it more readily to crooked logs; butmore particularly this capacity for adjustment is to cause the lower dogto serve as a means for preventing the log from being forced down toohard on the head-block, whether said dog is adjusted for a large orsmall log, and thereby allow the head block to be moved easier. Inwhatever position the lower dog is adjusted it will produce this result,without regardto the size oi' the log; and such adjustment is found tobe of special advantage in connection with the horizontal adjustment ot'the upper dog, so that both dogs can be set in or out, as may berequired for diierent size and shaped logs. j

A head-piece, A, firmly bolted to the headbloek, serves to support acenter-bar, B, which carries the dogs. This center-bar is secured to thehead-piece by a dovetail connection, G, which allows said bar to have avertical movement upon the xed head-piece to operate the dogs, the upperone D of which is secured in a slide, E, and the lower one F is pivotedto both the center-bar' and the head-piece, the fixed Eris recessedtotit overfthe center-bar B,and

is secured l"thereto byftong'ues c @,Vtittingiinto grooves iufthe sidesof said ban-'so as to allow it tofbe moved up: and down thereon.

The upper dog D is fitted in said `s'li'de so as to be lengthened orshortened, and it is secured by a spring-holt, G, fitted in a holder, H,and, passing through both the slide E and the dog D, enters holes d iuthe center-bar, thereby securing the slide vertically and the doghorizontally,l the latter having a series of holes, e, by which it maybe set in or out.

The lower dog F, as stated, is pivoted in a slot,b, to the head-piece.It is also pivoted, by a spring bolt, I, to the center-bar, within aslot in which the said dog is pivoted, and may be adjusted in or out byholes f, as may be required to suit dierentsize and shapes of' logs.

-By means ot' the long slot l) the dog may be adjusted in or out bychanging the springbolt l`in the holes in said dog. This adjustmentgives the advantage ot' causing the dog to take hold of (,lifterentsized logs without raising them 4from the head-block,as the eii'ect ofthe pivot-pin a is to cause the point to be raised a uniform distance,whether the dog be set in` or`out. For crooked logs the dog may be setin or ont, and always act with the same amount ot upward force upon thelog, yet-not lifting it from the head-block. By this means both dogshave a horizontal adjustment to suit the size and shape of' the log,

and both dogs have a vertical adjustment to enter and hold. the log sothat it cannot slip or turn at the lower side.

The descent of the center-bar brings down the upper dog and elevates theclaw of the lower dog.

To open the dogs the center-bar is raised. A eogged lever, J, pivoted tothe head-piece, Works into a pinion, K, which engages with a cogged baror rack, k, on the side of the center-bar B, serves as the means forraising and lowering the center-bar, and operating both dogs at onemovement of the lever. A springbolt,'L,-passes through the head-piece ator near its top, and takes into notches l in the center-bar to'keep thelatter from raising when the dogs are in position in the log. Aholdplate, M, serves to hold the springbolt L out of the rack whenoperating the center-bar.

To place the dogs in position to receive the log the center-bar israised, which turns the claw of the lower d'og down below the top orsurface ofthe head-block., The slide E is then raised and secured in thetop hole in said bar. The log is then rolled in place, and the upper dogbrought down with its cla-w upon the log. The center-bar is then forceddown hard by depressing the lever, and both dogs are put into the log,holding the bottom securely and firmly to the head-block, and keepingthe upper dog fr'oni bearing down too hard thereon.

The outer end ofthe spring-bolt L is square, and passes through acorresponding opening in the hold-plate M, nso that by drawing out thebolt and turning it a little a shoulder on it will catch outside of theplate M and hold the bolt out when moving the dog-carrying center-piece.

I claim- `1.-'Ihe combination, with the center-'bar B and the upper dogD, of the lower dog F, ad-

justable in and out by means of the slot b and lpivot-pin a, for thepurpose set forth.

2. p The lower dog provided with the slot b for the pivot-pin a, and theholes f, and arranged in a guideway in the center or dog bar, incombination with the springbolt I, adaptedto hold said dog when adjustedhorizontally by means of said slot, as described.

3. The dovetail center bar, having the toothed rack l, andthe head-piecehaving the spring-bolt L, the hold-plate M, and the levergear connectionwith said center-bar, combined for operation as described. y

In testimony whereof I have hereunto set my hand in the presence of twowitnesses.

HENRY SNYDER. I'

Witnesses JOHN G. GoULD, BENTLEY SABIN.

